Nonuniform segregation of Ga at AlAs/GaAs heterointerfaces

作者：Wolfgang Braun, A. Trampert, L. Däweritz, K. H. Ploog · 发表于：Physical review. B, Condensed matter · 年份：1997 · DOI：10.1103/physrevb.55.1689 · 被引用次数：63 · 研究领域：Electron and X-Ray Spectroscopy Techniques、Advanced Electron Microscopy Techniques and Applications、Surface and Thin Film Phenomena

Segregation at GaAs/AlAs (001) heterointerfaces has been studied experimentally by an in situ electron diffraction technique during molecular-beam epitaxy and by ex situ transmission electron microscopy. Whereas the GaAs-on-AlAs interface is abrupt, we find Ga segregating up to 20 crystal planes when depositing AlAs on GaAs(001). The measurements indicate an anisotropic in-plane structure of this interface with elongated ${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As regions extending along [1-bar10]. Our findings provide insight into both the segregation mechanism and electron diffraction from growing surfaces at glancing angles.